/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_BMP085 BMP085 Functions
* @brief Hardware functions to deal with the altitude pressure sensor
* @{
*
* @file pios_bmp085.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief BMP085 Pressure Sensor Routines
* @see The GNU Public License (GPL) Version 3
*
******************************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pios.h"
#include <pios_bmp085.h>
#ifdef PIOS_INCLUDE_BMP085
#ifndef PIOS_INCLUDE_EXTI
#error PIOS_EXTI must be included in the project
#endif /* PIOS_INCLUDE_EXTI */
/* Glocal Variables */
ConversionTypeTypeDef CurrentRead;
/* Local Variables */
static BMP085CalibDataTypeDef CalibData;
/* Straight from the datasheet */
static int32_t X1, X2, X3, B3, B5, B6, P;
static uint32_t B4, B7;
static volatile uint16_t RawTemperature;
static volatile uint32_t RawPressure;
static volatile uint32_t Pressure;
static volatile uint16_t Temperature;
#ifdef PIOS_BMP085_HAS_GPIOS
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreHandle PIOS_BMP085_EOC;
#else
int32_t PIOS_BMP085_EOC;
#endif
void PIOS_BMP085_EndOfConversion(void)
{
#if defined(PIOS_INCLUDE_FREERTOS)
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
#endif
/* Read the ADC Value */
#if defined(PIOS_INCLUDE_FREERTOS)
xSemaphoreGiveFromISR(PIOS_BMP085_EOC, &xHigherPriorityTaskWoken);
#else
PIOS_BMP085_EOC = 1;
#endif
#if defined(PIOS_INCLUDE_FREERTOS)
/* Yield From ISR if needed */
portEND_SWITCHING_ISR(xHigherPriorityTaskWoken);
#endif
}
static const struct pios_exti_cfg pios_exti_bmp085_cfg __exti_config = {
.vector = PIOS_BMP085_EndOfConversion,
.line = PIOS_BMP085_EOC_EXTI_LINE,
.pin = {
.gpio = PIOS_BMP085_EOC_GPIO_PORT,
.init = {
.GPIO_Pin = PIOS_BMP085_EOC_GPIO_PIN,
.GPIO_Mode = GPIO_Mode_IN_FLOATING,
},
},
.irq = {
.init = {
.NVIC_IRQChannel = PIOS_BMP085_EOC_IRQn,
.NVIC_IRQChannelPreemptionPriority = PIOS_BMP085_EOC_PRIO,
.NVIC_IRQChannelSubPriority = 0,
.NVIC_IRQChannelCmd = ENABLE,
},
},
.exti = {
.init = {
.EXTI_Line = PIOS_BMP085_EOC_EXTI_LINE,
.EXTI_Mode = EXTI_Mode_Interrupt,
.EXTI_Trigger = EXTI_Trigger_Rising,
.EXTI_LineCmd = ENABLE,
},
},
};
#endif /* PIOS_BMP085_HAS_GPIOS */
/**
* Initialise the BMP085 sensor
*/
void PIOS_BMP085_Init(void)
{
#ifdef PIOS_BMP085_HAS_GPIOS
#if defined(PIOS_INCLUDE_FREERTOS)
/* Semaphore used by ISR to signal End-Of-Conversion */
vSemaphoreCreateBinary(PIOS_BMP085_EOC);
/* Must start off empty so that first transfer waits for EOC */
xSemaphoreTake(PIOS_BMP085_EOC, portMAX_DELAY);
#else
PIOS_BMP085_EOC = 0;
#endif
/* Enable EOC GPIO clock */
RCC_APB2PeriphClockCmd(PIOS_BMP085_EOC_CLK | RCC_APB2Periph_AFIO, ENABLE);
if (PIOS_EXTI_Init(&pios_exti_bmp085_cfg)) {
PIOS_Assert(0);
}
/* Configure XCLR pin as push/pull alternate funtion output */
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = PIOS_BMP085_XCLR_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(PIOS_BMP085_XCLR_GPIO_PORT, &GPIO_InitStructure);
#endif /* PIOS_BMP085_HAS_GPIOS */
/* Read all 22 bytes of calibration data in one transfer, this is a very optimized way of doing things */
uint8_t Data[BMP085_CALIB_LEN];
while (PIOS_BMP085_Read(BMP085_CALIB_ADDR, Data, BMP085_CALIB_LEN) != 0) {
continue;
}
/* Parameters AC1-AC6 */
CalibData.AC1 = (Data[0] << 8) | Data[1];
CalibData.AC2 = (Data[2] << 8) | Data[3];
CalibData.AC3 = (Data[4] << 8) | Data[5];
CalibData.AC4 = (Data[6] << 8) | Data[7];
CalibData.AC5 = (Data[8] << 8) | Data[9];
CalibData.AC6 = (Data[10] << 8) | Data[11];
/* Parameters B1, B2 */
CalibData.B1 = (Data[12] << 8) | Data[13];
CalibData.B2 = (Data[14] << 8) | Data[15];
/* Parameters MB, MC, MD */
CalibData.MB = (Data[16] << 8) | Data[17];
CalibData.MC = (Data[18] << 8) | Data[19];
CalibData.MD = (Data[20] << 8) | Data[21];
}
/**
* Start the ADC conversion
* \param[in] PresOrTemp BMP085_PRES_ADDR or BMP085_TEMP_ADDR
* \return Raw ADC value
*/
void PIOS_BMP085_StartADC(ConversionTypeTypeDef Type)
{
/* Start the conversion */
if (Type == TemperatureConv) {
while (PIOS_BMP085_Write(BMP085_CTRL_ADDR, BMP085_TEMP_ADDR) != 0) {
continue;
}
} else if (Type == PressureConv) {
while (PIOS_BMP085_Write(BMP085_CTRL_ADDR, BMP085_PRES_ADDR) != 0) {
continue;
}
}
CurrentRead = Type;
}
/**
* Read the ADC conversion value (once ADC conversion has completed)
* \param[in] PresOrTemp BMP085_PRES_ADDR or BMP085_TEMP_ADDR
* \return Raw ADC value
*/
void PIOS_BMP085_ReadADC(void)
{
uint8_t Data[3];
Data[0] = 0;
Data[1] = 0;
Data[2] = 0;
/* Read and store the 16bit result */
if (CurrentRead == TemperatureConv) {
/* Read the temperature conversion */
while (PIOS_BMP085_Read(BMP085_ADC_MSB, Data, 2) != 0) {
continue;
}
RawTemperature = ((Data[0] << 8) | Data[1]);
X1 = (RawTemperature - CalibData.AC6) * CalibData.AC5 >> 15;
X2 = ((int32_t)CalibData.MC << 11) / (X1 + CalibData.MD);
B5 = X1 + X2;
Temperature = (B5 + 8) >> 4;
} else {
/* Read the pressure conversion */
while (PIOS_BMP085_Read(BMP085_ADC_MSB, Data, 3) != 0) {
continue;
}
RawPressure = ((Data[0] << 16) | (Data[1] << 8) | Data[2]) >> (8 - BMP085_OVERSAMPLING);
B6 = B5 - 4000;
X1 = (CalibData.B2 * (B6 * B6 >> 12)) >> 11;
X2 = CalibData.AC2 * B6 >> 11;
X3 = X1 + X2;
B3 = ((((int32_t)CalibData.AC1 * 4 + X3) << BMP085_OVERSAMPLING) + 2) >> 2;
X1 = CalibData.AC3 * B6 >> 13;
X2 = (CalibData.B1 * (B6 * B6 >> 12)) >> 16;
X3 = ((X1 + X2) + 2) >> 2;
B4 = (CalibData.AC4 * (uint32_t)(X3 + 32768)) >> 15;
B7 = ((uint32_t)RawPressure - B3) * (50000 >> BMP085_OVERSAMPLING);
P = B7 < 0x80000000 ? (B7 * 2) / B4 : (B7 / B4) * 2;
X1 = (P >> 8) * (P >> 8);
X1 = (X1 * 3038) >> 16;
X2 = (-7357 * P) >> 16;
Pressure = P + ((X1 + X2 + 3791) >> 4);
}
}
int16_t PIOS_BMP085_GetTemperature(void)
{
return Temperature;
}
int32_t PIOS_BMP085_GetPressure(void)
{
return Pressure;
}
/**
* Reads one or more bytes into a buffer
* \param[in] address BMP085 register address (depends on size)
* \param[out] buffer destination buffer
* \param[in] len number of bytes which should be read
* \return 0 if operation was successful
* \return -1 if error during I2C transfer
* \return -2 if BMP085 blocked by another task (retry it!)
* \return -4 if invalid length
*/
bool PIOS_BMP085_Read(uint8_t address, uint8_t *buffer, uint8_t len)
{
uint8_t addr_buffer[] = {
address,
};
const struct pios_i2c_txn txn_list[] = {
{
.info = __func__,
.addr = BMP085_I2C_ADDR,
.rw = PIOS_I2C_TXN_WRITE,
.len = sizeof(addr_buffer),
.buf = addr_buffer,
}
,
{
.info = __func__,
.addr = BMP085_I2C_ADDR,
.rw = PIOS_I2C_TXN_READ,
.len = len,
.buf = buffer,
}
};
return PIOS_I2C_Transfer(PIOS_I2C_BMP085_ADAPTER, txn_list, NELEMENTS(txn_list));
}
/**
* Writes one or more bytes to the BMP085
* \param[in] address Register address
* \param[in] buffer source buffer
* \return 0 if operation was successful
* \return -1 if error during I2C transfer
* \return -2 if BMP085 blocked by another task (retry it!)
*/
bool PIOS_BMP085_Write(uint8_t address, uint8_t buffer)
{
uint8_t data[] = {
address,
buffer,
};
const struct pios_i2c_txn txn_list[] = {
{
.info = __func__,
.addr = BMP085_I2C_ADDR,
.rw = PIOS_I2C_TXN_WRITE,
.len = sizeof(data),
.buf = data,
}
,
};
return PIOS_I2C_Transfer(PIOS_I2C_BMP085_ADAPTER, txn_list, NELEMENTS(txn_list));
}
/**
* @brief Run self-test operation.
* \return 0 if self-test failed
* \return any non-0 number if test passed
*/
int32_t PIOS_BMP085_Test()
{
// TODO: Is there a better way to test this than just checking that pressure/temperature has changed?
uint32_t passed = 1;
uint32_t cur_value = 0;
cur_value = Temperature;
PIOS_BMP085_StartADC(TemperatureConv);
PIOS_DELAY_WaitmS(5);
PIOS_BMP085_ReadADC();
if (cur_value == Temperature) {
passed = 0;
}
cur_value = Pressure;
PIOS_BMP085_StartADC(PressureConv);
PIOS_DELAY_WaitmS(26);
PIOS_BMP085_ReadADC();
if (cur_value == Pressure) {
passed = 0;
}
return passed;
}
#endif /* PIOS_INCLUDE_BMP085 */